Biomedical subjects

F C Tsui

Publications and source records attributed to F C Tsui.

9 recordsLinked to original sources

PubMed2001

The emerging science of very early detection of disease outbreaks.

A surge of development of new public health surveillance systems designed to provide more timely detection of outbreaks suggests that public health has a new requirement: extreme timeliness of detection. The authors review previous work relevant to measuring timeliness and to defining timeliness requirements. Using signal detection theory and decision theory, the authors identify strategies to improve timeliness of detection and position ongoing system development within that framework.

Bioterrorism↗

PubMed2001

Value of ICD-9 coded chief complaints for detection of epidemics.

To assess the value of ICD-9 coded chief complaints for early detection of epidemics, we measured sensitivity, positive predictive value, and timeliness of Influenza detection using a respiratory set (RS) of ICD-9 codes and an Influenza set (IS). We also measured inherent timeliness of these data using the cross-correlation function. We found that, for a one-year period, the detectors had sensitivity of 100% (1/1 epidemic) and positive predictive values of 50% (1/2) for RS and 25% (1/4) for IS. The timeliness of detection using ICD-9 coded chief complaints was one week earlier than the detection using Pneumonia and Influenza deaths (the gold standard). The inherent timeliness of ICD-9 data measured by the cross-correlation function was two weeks earlier than the gold standard.

Disease↗

PubMed1999

A feasibility study of two methods for end-user configuration of a clinical event monitor.

We developed and evaluated a feature that allows users to control what types of clinical information are delivered to them. Using a paper or web-based configuration form, users turn individual alerts and sets of results on or off, and set how they are delivered. We used usage rates to evaluate this feature. Of 16 residents who had received clinical information from our clinical event monitor, 4 (25%) made at least one change (range 10-25). Of 41 interns, 5 (12.2%) made at least one change (range 5-91). The difference was borderline significant (p < 0.1). 5/7 web users changed preferences through a dial-up connection from home. More users used the web-based preference form than the paper form. This difference may be due to the better accessibility of the web-based form. A survey established that this feature was not as highly utilized as anticipated partly because the initial (default) preference setting was acceptable and partly because the users were too busy to customize their alert settings. We conclude that user configuration of a system that delivers information using a web-based preference form is feasible and may become important as the volume of information and number of available communication channels increase.

Attitude to Computers↗

PubMed1999

Design of a clinical notification system.

We describe the requirements and design of an enterprise-wide notification system. From published descriptions of notification schemes, our own experience, and use cases provided by diverse users in our institution, we developed a set of functional requirements. The resulting design supports multiple communication channels, third party mappings (algorithms) from message to recipient and/or channel of delivery, and escalation algorithms. A requirement for multiple message formats is addressed by a document specification. We implemented this system in Java as a CORBA object. This paper describes the design and current implementation of our notification system.

Algorithms↗

PubMed1998

Mobile workers in healthcare and their information needs: are 2-way pagers the answer?

The ability to have access to information relevant to patient care is essential within the healthcare environment. To meet the information needs of its workers, healthcare information systems must fulfill a variety of functional requirements. One of these requirements is to define how workers will interact with the system to gain the information they need. Currently, most healthcare information systems rely on users querying the system via a fixed terminal for the information they desire; a method that is inefficient because there is no guarantee the information will be available at the time of their query and it interrupts their work flow. In general, clinical event monitors--systems whose efficacy relies on the delivery of time-critical information--have used e-mail and numeric pagers as their methods to deliver information. Each of these methods, however, still requires the user to perform additional steps, i.e., log into an information system in order to attain the information about which the system is alerting them. In this paper we describe the integration and use of 2-way alphanumeric pagers in CLEM, the UPMC Health System's Clinical Event Monitor, and how the use of these pagers addresses the information needs of mobile workers in healthcare.

Attitude of Health Personnel↗

PubMed1997

Clinical event monitoring at the University of Pittsburgh.

Although the literature on event monitoring is extensive, it does not cover all issues that we encountered while developing an event monitor at our institution. We had to resolve issues related to event detection, scalability, what topics were suitable for asynchronous decision support, and overlap of efforts of other groups at the institution attempting to improve quality and lower cost of care. In this paper, we describe our experience deploying CLEM, the clinical event monitor at the University of Pittsburgh with emphasis on these topics.

Academic Medical Centers↗

PubMed1997

Implementing NCEP guidelines in a Web-based disease-management system.

DMS is a Web-based disease-management system, which facilitates easy access for users and close connection to hospital information systems, based on clinical practice guidelines. Currently we are prototyping DMS in the area of hyperlipidemia management. However our approach is general. For each office visit, DMS generates an encounter form with recommendations based on the National Cholesterol Education Program (NCEP) guidelines. In between visits, DMS provides email notifications to clinicians about delinquent laboratory studies and recommendations for patient management based on recently available information. By reviewing previous efforts for implementing NCEP guidelines and some of the pitfalls that were encountered, we first constructed DMS for hyperlipidemia management. A detailed description of DMS is provided in this paper.

Cholesterol↗

PubMed1990

Distribution of charge on photoreceptor disc membranes and implications for charged lipid asymmetry.

A novel spin labeling technique is used to determine both the inner and outer surface potentials of isolated rod outer segment disc membranes and of reconstituted membranes containing rhodopsin with defined lipid compositions. It is shown that these potentials can be accounted for in a consistent manner by the accepted model of rhodopsin, the known lipid composition, and the Gouy-Chapman theory, provided the charged lipid is asymmetric in the membrane, with approximately 75% on the external surface.

Amino Acid Sequence↗

PubMed1986

The intrinsic pKa values for phosphatidylserine and phosphatidylethanolamine in phosphatidylcholine host bilayers.

Potentiometric titrations and surface potential measurements have been used to determine the intrinsic pKa values of both the carboxyl and amino groups of phosphatidylserine (PS) in mixed vesicles of PS and phosphatidylcholine (PC), and also of the amino group of phosphatidylethanolamine (PE) in mixed PE-PC vesicles. The pKa of the carboxyl group of PS in liposomes with different PS/PC lipid ratios measured by the two different methods is 3.6 +/- 0.1, and the pKa of its amino group is 9.8 +/- 0.1. The pKa of the amino group of PE in PE-PC vesicles, determined solely by surface potential measurements, is 9.6 +/- 0.1. These pKa values are independent of the aqueous phase ionic strength and of the effect of the liposome's surface potential due to the presence of these partially charged lipids.

Hydrogen-Ion Concentration↗